[thefro526]

In My personal opinion, Swerve > Mecanum > Holonomic, and this goes for just about any game.

If you've got the resources, both Manufacturing and Programming, go with a swerve. Swerve drives have the traction advantage over all of the other omni-drives out there. Swerve drives can be complicated to build and drive though, so be careful (Though, you could look into the team 221 swerve modules). Personally, if I ever built and omni-drive for any game I would build a swerve.

Mecanum Drives are probably the most accessible form of omni-drive out there. You can use the kit frame, AM Mecanums, and some off the shelf transmission and have a reliable Mecanum drive. Mecanums lack the traction of a swerve or traditional drive so watch out. Mecanums can climb decently though, so this is an advantage over a Holonomic.

Holonomic Drives are interesting. They're somewhere between a swerve and a mecanum in terms of build difficulty, due to the fact that the wheels must be mounted 90* from one another. (or 120*) They also can be a bit of a handful to drive, and they REALLY don't like un-level playing fields. Holonomic drives also don't push well.